Disinfection denotes the absence of pathogenic life forms. Sterilization connotes the absence of all life forms. Often, sterilization is measured against the elimination of bacterial endospores, which are the living organisms most resistant to conventional sterilants. "Decontamination" is used hereinafter to mean sterilization, disinfection or both.
Endoscopes are protectively encased bundles of flexible optical fibers used to transmit images to the operator at one end from otherwise inaccessible regions into which the opposite end of the instrument is inserted, so as to obtain a view of the structures surrounding such regions. Such an arrangement makes possible the visual examination, and even photographing, of structures surrounding cavities to which there is some external access, such access typically being a relatively small opening at some distance from the region of interest.
Not only can an endoscope be inserted into the region of interest and manipulated to permit viewing in different directions, but also such instruments are typically built to include means that allow the insertion of fluids into the region of interest. Often, there are also means for the removal of tissue from portions of the surrounding organ structures. Thus, in addition to the fiber optic bundle, there is usually provided a plurality of enclosed channels or passageways more or less paralleling the direction of the fiber optic bundle. These channels are also included within the enclosure that protects the fiber optic bundle. Specifically, such channels are typically provided to carry one or more of water, air and carbon dioxide gas. A further channel is often provided to permit the extension therethrough of the instrumentation needed to conduct a biopsy of tissue in the region of interest. This latter channel may also be connected to a vacuum source as a means for obtaining fluid samples. This biopsy/suction source typically has a larger diameter than the other channels.
Because endoscopes are complex, highly instrumented medical devices, they are too costly to be disposable. Therefore, it is desirable to reuse such devices. Because they are exposed to bodily fluids and tissue, both internally and externally, it is necessary to clean these devices thoroughly before they can be reused. The turn-around time on sterilization is relatively long, often on the order of days. This long turn-around time increases the need for medical decontamination equipment and requires a relatively high inventory of the devices themselves.
Medical equipment is commonly sterilized in a steam autoclave. Autoclaves kill life forms with a combination of high temperature and pressure. Autoclaves have several drawbacks. The high temperature pressure vessel tends to be bulky and heavy. Because the medical devices are made of rubber and plastic, the elevated temperature and pressure tend to reduce their durability and therefore their useful life.
Alternatively, medical equipment may be sterilized with an ethylene oxide gas, which is less damaging to the equipment than steam. However, ethylene oxide gas requires a relatively long exposure and an even longer degassing period. Also, ethylene oxide is toxic, volatile and relatively expensive.
In general, the equipment-decontamination devices presently used are generally very large machines, often of the dishwasher type variety. They are too bulky to fit easily into an endoscopy kit. In addition, they present the following disadvantages:
they require a significant volume of solution (in the order of at least 10 liters), and are therefore relatively costly to operate; PA1 they do not contain an integrated internal and external drying function; drying is performed in an additional module and typically lasts from 15 to 25 minutes; PA1 there is a risk of deterioration of the medical equipment, due to the lack of permanent control of its imperviousness throughout the disinfection cycle; PA1 rinsing is not performed with sterile water; PA1 there is a lack of automated disinfection of filters used in the device and filters clog frequently; PA1 there is incomplete immersion of the endoscope with mechanical washing effect; it is either immersed in a static solution or sprayed by rotating arms (dishwasher type), which does not ensure the efficient loosening and removal of organic matter; PA1 seals used to prevent leakage of the various solutions are insufficient for the use of foaming products; this lack of seal quality allows the disinfectant, which is generally noxious, to leak into the atmosphere; PA1 no safety controls are provided to prevent the operation of a cleaning cycle in the absence of sufficient disinfectant; and PA1 the machines are endoscope-specific and do not easily accommodate different medical devices.
The device according to this invention eliminates all of the disadvantages of the prior art. The invention provides a small, upgradable device which requires only simple and limited maintenance, uses a very small volume of solution in each full cycle and provides absolute safety, the complete removal of stains, and very fast integrated drying. In addition, because of its shorter cycle time, the device of this invention reduces the number of endoscopes needed. Further, the tightness of the seal of the device not only makes it possible to use foaming products, but also eliminates any release of disinfectant odors outside of the device itself.